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Full text of "Steel in the making."

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his is steel, newly-made, flowing 
in a molten stream from the open-hearth 
furnace. 



\$ e live in the Afie of Steel. Every 
necessity and convenience of our daily 
lives — food, clothing, shelter, modern 



FRONT COVER 

Pouring newly-made steel from 
a huge ladle into ingot molds. 






.«* -I* 




• •* 






■IP 











Open-hearth department of the Bethlehem 
Plant. Steel is being tapped into ladles 
simultaneously from three big furnaces. 




1 



I 








» 





STEEL 
IN THE MAKING 



STEEL— OUR MOST USEFUL METAL 

RAW MATERIALS OF 
STEELMAKING 

Iron Orr 

I imestone 

Vr. ip 

Water 

Air 

Human skills 

MAKING IRON IN THE 
BLAST FURNACE 

MAKING STEEL 

Open H-Mrili Pro- ,s 

r.l>-<tn< I iirn.n .• [*ro< <•,, 
It" ■ --••irn-r Process 

FLOW CHART OF STEELMAKING 

MAKING FINISHED STEEL 
PRODUCTS 

Plate* 

Miivt, and strip 

I in Plate 

Stl Mir;il Shape*) 
Ban 

Rod and 1 ire Prodi * 
Tubular Product* 

Rails 
BETHLEHEM PRODUCTS 



I 'tit: 



4 

5 

6 

7 
7 
8 
8 



10 

12 
13 

i 

16 



19 

21 
22 
25 
26 
8 

32 
34 

5 



methods of transportation and nimiuii- 
nidation — all depend in some way on 
tins most useful of metals. 



In this hook we tell von ho* *l< I is 
made, and describe a few of the countless 
>wi\- in whirh it serve* ns all. 






The photograph* steel- 

mok ,' inril, , n ,l ftro , ies 

mppemrmg pmbii n 

were taken in /i-rhlehem's 
steelmnkim- plants, << rh are 
lor il ns follows 

BETH1 EHEM. PA. 
SPAMKOW5 POINT \li> 

LACKAWANNA N 

TEKf \>\ 

JOHNSTOWN, P\ 

SOI TH >\\ PRANQ \i if 

LOS W< CALD 

SEATT1 • KSh 




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9 _ 



erht I l. RrthUk**. ,„/ r — 







our most 



useful metal 



In the modern, highly industrialized era in which we are 
living, steel occupies a fundamental place. Today there is 
hardly any activity that does not depend on steel in some 
way, direct or indirect. Steel in its many forms is serving 
in countless ways to make our lives more enjoyable and 
more productive. 

Of all metals steel is the most abundant and the least 
expensive — costing only about 4*4 cents per pound on 
the average — due to the modern, efficient production 
equipment and methods of the steel industry. 

Steel has a combination of properties — strength, hard- 
ness and toughness — that is unequalled by any other ma- 
terial. But even more important is the fact that we can 
accurately adjust and control these properties within wide 
limits. We can make steel exceptionally hard or relativel) 
soft; that is why tools made from certain steels can be 
used to cut other steels. And special steels can be made 
to resist heat, wear, shock and corrosion. 

Then, too. sleel can be processed into so many different 
forms. It can be made into wire as fine as a hair, yet 
amazingly strong. It can be rolled into thin, flat sheets, 
then formed into the curving contour- of an automobile 
fender. It can be forged into objects large or small, from 
hammer heads to propeller shafts for huge ocean liners. 

The Beginnings of Ironmaking 

The history of steel and that of its parent metal, iron. 
are closely interwoven. It was probably during the New 
Stone Age that primitive man learned to make iron by 




heating rocks and earth containing iron oxide in an open 
fire. Gradually he added improvements. He built stone 
hearths, used crude bellows to make hotter fires, and sub- 
stituted charcoal for wood. Such simple furnaces provided 
man's supply of iron for many years. 

The earliest writing to mention ironmaking is the Book 
of Genesis, where it is recorded that Tubal-Cain, seven 
generations after Adam, forged cutting instruments of iron. 
The oldest objects made of iron that are still in existence 
are the remains of iron beads found in an ancient Egyptian 
cemetery dating back to 4000 B. C. There is also evidence 
that the Egyptians used iron tools when they built the 
pyramids as early as 3100 B. €♦ 

Ancient writings indicate that the Chinese made iron 
around 2200 B. C. Skilled artisans in India, Korea and 
Japan made and used iron and steel many centuries ago. 
From India came a fine grade of steel which the Syrians 
used in forging the famous swords of Damascus. 

In the Middle East the Persians, Medes, Hittites and 
Phoenicians carried on a trade in iron long before the 
Christian era. It was probably the Phoenicians who intro- 
duced iron to Greece. Rome, Spain and France, and so 
to all the Western world. 

Homer's writings, which date back to about 850 B. C, 
tell us that the prizes awarded winners of Olympic contests 
were sometimes made of iron. Iron was also made and 
used by the ancient people of Britain, France and Spain. 
However, the military use of ferrous metals was most 
highly developed by the Romans, whose legions were 
equipped with excellent iron and steel armor and weapons. 

Early Progress in Ironmaking 

One of the first important advances in ironmaking is 
credited to the Spaniards. The Catalan forge, developed in 
Catalonia in northern Spain, probably before the eighth 
century, produced considerable quantities of wrought bar 
iron. Another early ironmaking furnace was the stuckofen, 
first used in Germain and Austria, a crude version of the 
present day blast furnace. 

As these and other furnaces made an increased supply 
of iron available during the late Middle Ages, European 
artisans became remarkably skillful in the art of forging 
iron and, sometimes, steel bars. They produced numerous 
metal tools, weapons, cooking utensils, locks and — their 
supreme achievement — richly ornamented suits of armor. 
Until the invention of gunpowder, the knight in armor re- 
mained practically invulnerable to the weapons of the day. 

In earlier times steel was thought to be simply a superior 
grade of iron. By the seventeenth century, however, Euro- 
pean ironmasters understood the basic difference between 
iron and steel — steel being a refined form of iron —and 
were producing steel in small quantities. One early use of 
this steel was the fine cutlery for which the town of Sheffield, 
England, is famous to the present day. 



In this primitive forging method two crude bellows pro- 
duce o fire hot enough to make iron soft and workable. 



2 












This skillfully made suit of steel 
armor is a striking example of the 
amazing ability of medieval smiths. 





Early blast furnace near Pottstown, Pa., which operated for 134 years. 




















/ 
















This simple cast 
iron cooking pot 
was made at the 
Saugus Works in 
mid-1 7th century. 



Steelmaking in America 

Early in the seventeenth century the London Company 
built the first ironworks in the New World at Falling Creek 
in Virginia. But in March, 1622, just as operations were 
starting, Indians attacked the settlement, destroying the 
works and killing 347 colonists. The only survivor was 
young Maurice Berkeley, son of the leader. 

Another Colonial ironworks — recently rebuilt accord- 
ing to its original design — was completed in Saugus, 
Massachusetts, in about 1650. One of the first iron articles 
made there, a simple cooking pot. is still in existence. 

It was not until the latter half of the nineteenth century 
that any significant progress was made in producing steel 
in large quantities. Then two men. Sir Henry Bessemer, an 
English engineer, and William Kelly, an American iron- 
master, independently developed the method of converting 
pig iron into steel now known by Bessemer's name. 

For some years nearly all the steel produced was made 
1>> the hessemer process. However, late in the nineteenth 
century the more efficient open-hearth process was devel- 
oped. By 1909 more steel was being made in open-hearth 
furnaces than in bessemers. A later development was the 
introduction of the electric-furnace process. 

The growth of the steel industry has been nothing short 
of phenomenal. In 1890 America^ steel furnaces poured 
5 million tons of steel; in 1917. 50 million tons: in 1953, 
nearly 112 million tons, about 43 percent of the entire 
world output. This tremendous increase in steel produc- 
tion has been closely interwoven with the industrial ad- 
vances of the twentieth century that have given the people 
of the United States the highest standard of living the world 
has ever known. 

Today, steel is the backbone of our economy — our 
greatest strength in peace and in war. 



3 



TH 




RAW MATER I 




O 





COAL 











Four basic raw materials — iron ore, coal 
limestone and scrap metal are used to make 

teeL • 

The first step of steelmaking, the making of 
iron, requires iron ore coal (after it has been 

converted into coke) and limestone. 



The second step is converting the iron, to 
which scrap meted is added, into steel. 



Open-pit mining at Bethlehem 
mine at El Pao, Venezuela. 
Power shovels scoop up the ore, 
which lies close to the surface. 





LMAKING 



Iron Ore 

The basic source of all iron and steel is iron ore, which 
consists of iron oxide combined with alumina, silica, 
phosphorus, manganese and sulphur. Small amounts of 
iron are found almost everywhere. But the areas in which 
iron ore is mined are relatively few. It costs so much to 
provide facilities to extract the ore from the earth and 
transport it to the steel mills that the expense can be 
justified only when the ore is of high grade and present in 
large deposits. 

Most of the iron ore mined in this country has been of 
two types: hematite and magnetite, both of which aver- 
age about 70 percent in iron content when pure. Hematite 
has a brick-red color. Magnetite is black. 

Both Domestic and Foreign Ores Used 

The leading iron-producing region in the United States 
is the Lake Superior district of Minnesota, Michigan and 
Wisconsin, which includes the famous Mesabi Range. 
Other important ore-producing areas are in Pennsyl- 
vania, New York, New Jersey and Alabama, and in a 
number of the Rocky Mountain states. Steel mills in the 
United States also import ore from Canada, South Amer- 
ica, Europe and Africa. 

Bethlehem Steel Company uses ore from several of 
these sources. Large tonnages come from the Lake Su- 
perior district, from the Cornwall Mine in eastern Penn- 
sylvania, which dates back to the American Revolution, 
and from Bethlehem mines in Venezuela and Chile. 
Supplementing these sources, we import special types of 
ore from Sweden. Bethlehem is also developing several 
new sources of ore, including the Grace Mine near Mor- 
gantown, Pa. ; a deposit at Marmora, in the Province of 
Ontario, Canada; and in Chile. In addition, this company 
plans to use ore from the large deposits in Labrador that 
are now being developed. 




These ore unloaders are scooping iron ore 
from the hold of a vessel in 17-ton bites. 

Taconite— A New Source of Iron 

Another vitally important source of iron for the near 
future is (aconite. This extremely hard rock, containing 
particles of iron oxide, is found in vast quantities sur- 
rounding high-grade ore deposits. However, taconite is 
too low in iron content in its natural state to be used in the 
iron-making blast furnaces. In order to solve this prob- 
lem, several groups of steel companies have constructed 
pilot plants where the\ have developed a way to extract 
the iron oxide from taconite and concentrate it in marble- 
sized pellets with iron content of about 65 percent. One of 
the leaders in this research work has been Erie Mining 
Company, in which Bethlehem has a sizable interest. Erie 
is now building a full-scale plant where large quantities 
of taconite will be prepared for steelmaking. 




A new source of iron ore is the Grace Mine, near Morgantown, Pa. Ore deposits, 1500 to 3000 feet underground, are reached by shafts and tu 



nnels. 



5 





Discharging incandescent coke from oven. The coke is then quenched 
under sprays of water to prevent it from burning in the open air. 



Coal mine at the Johnstown Plant, only steel plant in the 
U. S. located directly above large deposits of coking coal. 



Coal 



Coal is another of the basic raw materials of steel- 
making. It is used to make coke which, in turn, is used 
as fuel in the blast furnaces where iron is made. Coking 
coal, a special type of bituminous or "soft" coal, is mined 
principally in western Pennsylvania. West Virginia — 
Bethlehem has mine- in both these states — and in Illinois 
and Alabama. 

Machinery has taken the place of pick-and-shovel work 
in mans modern bituminous coal mines. Mechanical 

(Utters slice into the solid blocks of coal, which are then 

blasted loo j explosives. M hanical loaders gather 
up the coal and load it onto ears which carry it to the 
urface. Recentl) machines have been introduced that 
mine and load tie I in one operation, thus eliminating 
th< i d for- blasting. Finally, the coal is mechanicalh 
crushed, sorted, washes ind blended, in preparation for 
use in the coke o\ ens. 

Coal is "Baked" in Coke Ovens 

Coke ovens, which are located at the steel plant, are 

large rectangular ovens, usualh arranged side b\ side in 

atteries of 40 or mori I he newi si ovens arc approxi- 

natel) in feel long, about 13 feel high, and between 

1 and 2 feet wide. 

d i ;l is dumped into the oven through i en- 

il in the top. The oven is cl <L heated to about 
2000 degr< F and kepi at this temperature for 19 or 20 
houi le the intense heal is driving off the various 

gases in tin d. Tie solid matter which remains is 




pushed from the oven while glowing with heat and is 
quenched under spra\ s of water. The result is coke, a 
firm, porous, gray substance, about 85 percent carbon. 

Coke is the ideal fuel for the blast furnaces. It burns 
rapidly with intense heat and supplies the carbon needed 
to make carbon-monoxide gas which plays a vital part 
in the blast-furnace process. Furthermore, coke has a 
strong enough structure to support the tremendous weight 
of the iron ore and limestone which are charged into 
the blast furnace. 

Coking Process Yields Valuable Gas 

For ever) ton of coke, an oven produces 16,000 to 
18,000 cubic feet of coke-oven gas. This gas is extremely 
important both as a source of byproduct chemicals and 
as a fuel for use within the steel plant. 

The gas passes from the ovens into a system which 
recovers the primary byproducts such as tar, ammonium 
sulphate, naphthalene, p) ridine and light oils. These basic 
chemicals an further processed to yield tar-acid oils, 
enzol, toluol, w lob etc. Other industries use these chemi- 
- als to make nylon, synthetic rubber, aspirin, TNT, moth 

balls. jM-rfumes. dyes, sulpha drugs, plastics and thou- 
sands of other well-known products. 

After the coal chemicals have been extracted, the gas 

that remains is used as fuel for the coke ovens, the open- 
hearth furnaces, and for other processes within the steel 

plant. In addition, some plants supply coke-oven gas to 
surrounding communities for use as a household fuel. 



Deep in a modern mine a big 
mechanical loader scoops up 
the loosened chunks of coal 
and loads them into mine cars. 







Byproducts of coke-mak- 
ing, processed in this plant, 
are sold to chemical indus- 
tries for conversion into 
many familiar products. 




Limestone 

Limestom- ,, ., lv roc k consisting K of • > i r >i 
irbonate i i y ed in bias! furna< < ami to a smsllei 

r "ctent, in the open hearth furnai I ,im ■ i 

clean i i 01 flux, loaking up the impuriti md formin 

.1 stum like slag, I ifiirsiun,- h,, us r hi Hi Imakm 

from Bethlehem quau n Hiere ii i^ H I ami rrual 
in preparation foi use in the furnai - 



• urn 



Scrap 



Oho of the rnosi i portanl in es of new steel i- old 

ileel mil iron No matin bov\ old and rust) the r .« I 

ma) become, it can always be melted down I i n« 
verted into new steel. In la. I iteel plan it do hai 

bl;i*t furnai often make §teel rntireN fi n ferrous 
wrap But undei ordinar) steelmakii mditi afn»ut 
one-hall of the iron content of steel come* from molte 



pig ii on ami the remain dei from -« » s| 



This quarry near Bridgeport, Pa., supplies limestone for ifeelmaking 




7 






' dlj tWCJ kind- of M I l|> ||r l| d in I 

rriuk. i i II-. ,, , vx l( ( t \ lt , | } ,| ,,,, 

itself f^ oi n ei \ ton I pmdu< ml) i ul thi 

•l ,Mr M ' f - • r ni *hifi u| I he n i initi 

i irtei ton *hi I , , „,, 

tui ii"l tcj rfi linaki u run 

( Hit*id< |i is uau i ,, ,,, 

♦ *h< >Hn i i | , IMS f 0| ., (1 . r|0 | ( | M . r 

* ,s< ! " In It In, i if! ,,- ,|, | hr- C 

*° U r " S ' H- ill r ,,,,) 

*rU -u« h b h.i i rlrd ii limrry, I 

hi| and old railwa) i I i |« taothei -an 

fl h '" i '" 1 A™ ii. iin hope 

md her pl.ii r* when ft aJ work 

An Example of the 'Rebirth" of Steel 

1 rl "- H al i \\ Id 1 II rail 

n ' ' ' r! I •< -fi • md repl* i the 

with d I l Id l 

ton- nf -i 



d rrpl -ii me 

r ihi ni'N i 

hk h wai d in! 

I*«i«' e» ami arts of tf 



Retired locomotives provide icrap for conversion into ne 





The Sparrows Point Plant, near Baltimore, second largest steel plant in the world, and largest on the Eastern 
Seaboard. Sparrows Point, with annual steelmaking capacity of approximately 6,000,000 tons, has a normal 
payroll force of 25,000 employees, and an annual payroll of over $100,000,000. More than 15,000 electric 
motors supply 600,000 horsepower for use in the plant. Every day the plant consumes about 550 million 
gallons of water, more than is used in the nearby city of Baltimore, sixth largest city in the United States. 



Water 

Steelmaking takes tremendous amounts of water — 
20,000 to 25,000 gallons of water for each ton of steel 
produ< I Steel plants use water for cooling equipment 
and structures such as blast furnaces and open hearths. 
It is al ed for the generation of steam, for the cleaning 

rid cooling of blast-furnace and coke-oven gases, and for 
cooling steel during processing. 



Air 

It is an amazing fact that the air used in steelmaking 
actually outweighs the solid raw materials. Oxygen in 
the air permits the fuels used in steelmaking to burn, and 
assists in the various chemical reactions. From 4 to 4^A 
tons of air must be supplied to a blast furnace in order to 
make 1 ton of pig iron. Another ton or so of air is needed 
in converting the iron into steel. 



8 



The 1 1 -billion-gallon reservoir on Quemahoning Creek, one of four needed 
to supply the Johnstown Plant with 140,000,000 gallons of water per day. 



This 1 1,150-horsepower turbo-blower supplies air for the Steelton Plant's 
big blast furnaces. It takes about 5 tons of air to make 1 ton of steel. 






Workmen rebuilding open-hearth furnace 
with refractory bricks. Such maintenance work 
is a never-ending job in a large steel plant. 




Electricity supplies most of the power used 
in steelmaking. These massive electric mo- 
tors drive the rolls in a sheet-strip mill. 







Electric power for Sparrows Point 
is generated in this huge steam plant 
which uses blast-furnace gas for fuel. 



Human Skills 



If you visited a steel plant, you might be so impressed 
by the size and complexity of the furnaces and mills 
that you would overlook the all-important human element 
in steelmaking. It takes people — many different kinds of 
skill — to make steel. 

Our Sparrows Point Plant, for example, has a normal 
payroll force of 25,000 employees. Of these, 6,000, or extent mechanized equipment is used in steelmaking. 

about one out of every four, are engaged in maintenance, 



meant hard labor. This mechanization in steelmaking 
does more than save human drudgery. It increases effici- 
ency, thus producing more steel at lower cost. 

Electric Power in Steelmaking 

Here are a few figures that give an indication to what 



The power needed to produce 1 ton of steel — to oper- 
service and transportation work alone. They include at e the furnaces, rolling mills and many other facilities 

carpenters, electricians, machinists, bricklayers, painters, within the plant — amounts to about 700 horsepower- 

truck drivers, firemen and plant patrolmen. The 19,000 hours. A large steel mill such as our Lackawanna Plant 

employees directly engaged in the production of steel requires electrical installations as large as those of a city 

include hundreds of other specialized skills. These skills of 100,000 population. The 12,000 or so electric motors in 

are based on years of experience. Almost one-half of all tne Lackawanna Plant deliver over 500,000 horsepower. 

Bethlehem employees have been with the company for 
from 10 to 45 years or longer. 

There is no substitute for human skills in steelmaking. 
But the part that human muscles play in the operation of 
a steel plant is much less than it was only a few years 
ago. Today everywhere you turn in a big steel plant you 
see machinery making short work of tasks that once 






9 






sua* 





Tapping a blast furnace. Molten pig iron runs 
down a trough to the left. The workman 
at center is taking a sample for analysts. 













Iron ore is converted info pig iron by means of a 
series of chemical reactions that take place in the 
blast furnace. 

First — heated by a hot blast of air from the stoves, 
the coke burns, creating gases. 

Second — these gases rear! with iron oxides in the 
ore, removing the oxygen and leaving metallic iron. 

Third — the limestone (rentes a slag which absorbs 
much of the silica and other impuril 5 from the ore. 










ONE OF THREE 
OR FOUR STOVES 
FOR HEATING AIR 



REFRAC10RY 
IRICK LINING 



• RICK 
CHECKERWORK 



AIR IS HIAUD 

AS IT RISES 

THROUGH 

HOT IIKKWOM 




SKIP CAR 1 



Simplified cutaway diagram of a typical blast- 
furnace installation, including one of its stoves 





Spectacular skyline of the Bethlehem Plant along the Lehigh River. The blast furna 



ces tower over other steel-plant structures. 



oni 



A blast furnace, together with its stoves and other 
equipment, makes a huge and complicated structure. But 
its basic design is quite simple. As shown in the diagram, 
the blast furnace is essentially a tall, brick-lined steel 
shell, approximately cylindrical in shape. The typical 
blast furnace is well over 100 feet in height, with a 
hearth diameter of 25 feet or more, and a daily output 
of between 800 and 1700 tons of iron. For example. 
Furnace "D" at our Bethlehem Plant is 237 feet high 
with a hearth about 29 feet in diameter. It can produce 
1600 tons of iron daily. 

Skip cars, running up and down an inclined track, 
carry the charge — iron ore. coke and limestone — fr 
bins in the stock house to the top of the blast furnace 
where they are dumped into the furnace through a hopper. 

The very large pipes that are an important part of the 
blast furnace bring preheated air to the furnace and 
carry away the gases that are produced. 

Preheating Air for Blast Furnace 

Three or four tall cylindrical structures, sometimes 
over 100 feet high, stand close to the blast furnace. These 
are the stoves that heat the air before it is blown into the 
furnace. They contain thousands of heat-resisting bricks 
arranged in a checkerboard pattern which permits gas 
and air to pass through. First, gas from the blast furnace 
is burned in one of the stoves, heating the bricks in its 
interior. Then the gas is diverted to another stove and the 
air being blown into the furnace is routed through the 
first stove. As the air rushes through the hot brickwork 



3000 degrees F. The molten iron trickles down through 
the charge and collects in a pool on the hearth. 

At the same time, the intense heat converts the lime- 
stone into lime, which combines with most of the silica 
and other impurities from the iron ore and coke, forming 
molten slag. This slag drips down to the hearth where it 
floats on top of the heavier iron. 

The iron is tapped every five or six hours: the slag is 
removed more frequently. These casts of iron average 
from 150 to 350 tons, according to the size of the furnace. 
The molten iron is taken to the steelmaking department of 
the plant where it is kept hot in an enclosed container 
called a hot-metal mixer. It is later converted into steel by 
either the open-hearth or bessemer processes. 

Blast furnaces operate continuously, day and night, ex- 
cept when they are shut down for repairs, or for relining, 
which is normally required every four or five years. 

Uses of Blast-Furnace Slag and Gas 

For even ton of iron, the blast furnace produces about 
half a ton of slag and six tons of gas. After this gas has 
been cleaned, some of it is used in the stoves. The remain- 
der serves as fuel for other processes in the plant. 

The slag, poured into pots mounted on cars, is hauled 
away to the slag dump. Large quantities of slag are sold 
for use as aggregate in concrete. Some is processed into 
rock wool, commonl) used to insulate homes. 

Characteristics and Uses of Pig Iron 

Iron from the blast furnace may contain about four 
it absorbs heat stored in the bricks, which raises its percent carbon, one percent or less silicon, one and one- 

temperature to about 1000 degrees F. hot enough for half . P en ' ent manganese, and much smaller percentages 

use in the blast furnace. 



How the Blast Furnace Works 

The raw materials are charged into the furnace in 
alternate layers of iron ore, coke and limestone. The hot 
air from the stoves is blown into the furnace through 
tuyeres near its base. The oxygen in the air reacts with the 
carbon in the coke, forming carbon-monoxide gas and 
creating intense heat. The gas rises through the charge, 
combining with the oxygen in the iron oxides and reduc- 
ing the ore to metallic iron at a temperature of about 



of phosphorus and sulphur. It is hard and brittle, lacking 
the great strength, ductility and resistance to shock that 
steel possesses. Articles made of iron I then called cast 
iron because they are shaped by pouring, or "casting 
molten pig iron into molds! are rigid and have great 
compressive strength, so that they will support a very 
heavy weight; but they generally are brittle, and shatter 
readily under blows. However, cast iron has many uses, 
such as for automobile-engine blocks, and for a wide 
variety of machinery parts. But most pig iron by far is 
used to make steel, as described on the following pages. 



11 



Steel is refined pig iron. The refining process further 
reduces the amount of impurities present in the metal. 
Technically speaking, steel is essentially iron com- 
bined with carbon, the carbon content ranging from a 
few hundredths of 1 percent up to about I AG percent. 
All steel also contains some manganese, silicon, phos- 
phorus and sulphur. 

Over 90 percent of all steel made is classified as 
carbon steel, meaning that it contains a regulated 
amount of carbon and only slight traces of other ele- 
ments. Most of the steel used in buildings, bridges, and 
other structures; in common tools such as hammers, 
screwdrivers and saws; in bolts and nuts, nails, farm 
fem ng, and thousands of everyday articles, is plain 

arbon steel. 

The remaining 10 percent or so consists of alloy 
steels. An alloy steel is steel to which have been added 
carefully determined amounts of alloying elements such 
as manganese, nickel, chromium, vanadium, molybde- 



num, etc. These alloying elements impart certain highly 
desirable properties to the steel, such as exceptional 
strength and ability to withstand very high or very 

low temperatures. 

The refining process by which the excess carbon and 
impurities in the pig iron are eliminated, converting the 
iron into steel, may be carried out in either the open 
hearth or the bessemer converter. The methods of steel- 
making are described on the following pages. 








Simplified cutaway diagram of 
a typical open-hearth furnace, 
viewed from the tapping side. 



Open-hearth charging floor at the Saucon Division of the Bethlehem Plant, where steel is made for rolling into structural shapes 



<&3 















Taking a sample of slag from open hearth 
for analysis in the metallurgical laboratory. 




Tapping an open hearth. Molten steel fills the 
ladle; the slag spills over into the slag pot. 



Teeming ingots. The molten steel is 
poured into molds where it solidifies. 



Open-Hearth Process 



More than 90 percent of all steel produced in the 
United States, including both carbon and alloy grades, 
is made in open-hearth furnaces. The name "open hearth" 
comes from the fact that the pool of molten metal covered 
with slag lies on the hearth of the furnace, exposed to 
the sweep of flames. The excess carbon is oxidized by is continued. 

oxygen from the iron oxide, while the slag absorbs im- 
purities. In this way the molten metal is refined into steel. 

Modern open-hearth furnaces are usually about 70 
feet long and 20 feet wide. As shown in the diagram, 
there are doors on the front or charging side of the fur- 
nace. The back or tapping side of the furnace has a tap 
hole through which the finished steel flows from the fur- 
nace into a ladle. This hole is kept sealed with a refractory 
plug until the steel is ready for tapping. 



Air is Preheated in Checker Chambers 

Beneath the furnace are two checker chambers. They 
contain bricks arranged in a checkerboard pattern, per- 
mitting the alternate passage of air and exhaust gases. 

Preheated air from one checker chamber enters at one 
end of the furnace, where it mixes with gas or other fuel. 
This air-fuel mixture is blown into the furnace, burning 
as it sweeps across the pool of molten metal in the hearth. 
The hot exhaust gases pass out the other end of the fur- 
nace into the opposite checker chamber, where they heat 
the brickwork to a high temperature. Every 10 or 15 min- 
utes the direction of flow is reversed, so that while the 
brickwork in one chamber is being heated by the hot 
exhaust gases as they rush from the furnace, the hot 
checkerwork in the other chamber is heating the air that 
is entering the furnace. 

How the Open-Hearth Furnace Works 

First, limestone is put into the furnace. Its purpose 
in the open hearth is the same as in the blast furnace: 
it removes impurities and builds up a slag. Next comes 
iron ore I or some other source of iron oxide I which sup- 
plies the oxygen needed to oxidize the excess carbon. 
Then steel scrap is placed in the furnace. Normally about 



one-half of the metal charged into the open hearth is 
scrap and the other half is pig iron. After the scrap has 
been partly melted, the pig iron, which has been kept in 
a molten state in a hot-metal mixer, is poured into the 
furnace. Finally, more iron ore is added, and the melting 



Next follows the refining or purification period, during 
which the excess carbon is oxidized and other impurities 
are absorbed by the slag. The (lames sweeping across the 
surface of the molten metal bring it to a temperature of 
about 2800 degrees F. This intense heat creates such a 
dazzling glare that it is impossible to look into an open- 
hearth furnace without special glasses. 

From time to time during the refining period samples 
are taken of the metal and sometimes of the slag. These 
samples are rushed to the metallurgical laboratories for 
quick checking and analysis, which provides information 
necessary for proper control of the refining operation. 

If alloy steel is being made, the alloying materials 
are added at the proper time. 

The entire process of making a heat of steel takes up 
to 12 hours. When the steel has been refined to the 
exact specifications called for. the heat is tapped. The 
plug in the tap hole at the rear of the furnace is punetured 
with a rocket-like explosive charge. The steel gu-hes out 
in a bright stream, down over a spout and into a huge 
ladle. The slag, which leaves the furnace after the steel, 
spills over into a smaller container called a slag pot or 
thimble, which is later taken to the slag dump. 

Molten Steel Poured Into Ingot Molds 

Most modern open-hearth furnaces produce from 150 
to 250 tons of steel in each heat. After tapping the furnace 
is charged again and the process is repeated. 

Steel made in the open hearth, or in the electric furnace 
or bessemer converter as described in the following pages, 
is poured or teemed into ingot molds where it cools and 
solidifies. The ingot is the first solid form of steel. Ingots 
usually range between 5 and 25 tons, although much 
larger ingots have been poured for special purposes. 



13 



ELECTRODES 



Diagram of arc-type electric furnace. It is nearly round 
in shape and can be tilted to pour out the finished steel. 



REFRACTORY BRICK 
LINING 



[HARGING 
DOOR 




METAL BATH 



PATH OF ELECTRIC ARC 




Tapping a 75-ton electric furnace at the 
Bethlehem Pacific Plant in Los Angeles. 




Electric-Furnace 

Process 



Most electric-furnace steel is made in furnaces of the 
electric-arc type, in which the "bath" of molten metal is 
heated by an electric arc. Both the temperature and the 
atmosphere can be very closely controlled, making the 
electric furnace ideal for producing steel to exacting 
specifications: high-alloy steels, stainless steels, or special 
steels requiring very close metallurgical control. 

However, in recent years there has been a growing 
trend toward the production of carbon steels in the elec- 
tric furnace, especially in smaller plants, and in locations 
where large supplies of ferrous scrap are available. 

Electric furnaces vary in capacity from 5 to 100 tons. 
They somewhat resemble a teakettle in shape, and are 
tilted to pour out the finished steel through a spout. Three 
carbon electrodes extend down through the roof of the 
furnace. The metallic charge is inserted through a door 
on one side or through the top of the furnace which can 
be swung to one side. 

How the Electric Furnace Works 

The initial charge consists of carefully selected steel 
scrap. The electrodes arc Lowered and the current is 
turned on. The intensely hoi arcs between the electrodes 
and the scrap quickl) form a pool of molten metal di- 
rectly under the electrodes and. in effect, enable the elec- 
trodes to bore into the scrap. After the chare i- about 
TO percent melted, iron oie and burnt lime are added, 
and melting is completed. At this point, samples of the 

bath are analyzed in the metallurgical Laboratory. 

The next step |>enda on the kind of sti i I being made. 
If it is carbon steel, the «, juration is rather similar to 
that of the open hearth. If an alio) steel is being mad« 
the initial -lag is removed and a second slag is made t 
permit dose control of the final analysis. \11 additions 
to the bath — the materials added to form the second sfa 

and the alloying materials— are in the form of carefully 
fried material of known composition. The entire pro 

take- from 4 to 12 hours, depending on the t\jje of steeL 



14 



Diagram of a bessemer converter. As the metal is refined 
brightly flaming gases burst from the mouth of the vessel! 



Bessemer 
Process 

Development of the bessemer converter in the 1850's 
marked the beginning of the modern steel industry. This 
is the oldest of the three steelmaking processes in use 
today. In the bessemer process the charge of molten pig 
iron is refined into steel by blowing air through it, thus 
oxidizing or burning out undesirable elements. 

A bessemer converter, as shown in the accompanying 
diagram, is a pear-shaped vessel 10 feet or more high, 
open at the top, and mounted on trunnions so that it can 
be tilted. Holes in the bottom permit air to enter and 
pass up through the charge of molten pig iron. Depending 
on the size of the converter, between 12 and 30 tons of 
steel can be made in a 12- to 20-minute "blow." 

How the Bessemer Converter Works 

First, the converter is tilted forward and molten pig 
iron is poured in at the top. The vessel is then returned 
to an upright position and a blast of air is blown in at 
the bottom. As the air passes upward through the pi 
iron, the oxygen it contains burns out the undesirable 
elements, forming slag and gases. The gases burst from 
the mouth of the converter with a brilliant shower of 
smoke, sparks and flame, making one of the most spec- 
tacular sights in steelmaking. When the process has been 
completed the converter is tilted and the steel poured 
into a ladle, from which it is teemed into ingot molds. 

Bessemer Steel 5% of Total 

In the early days of the steel industry, up to around 
the turn of the Century, most steel was made in the 
bessemer converter. The first steel rails made in this 
country for our expanding railway system were made 
from bessemer steel. But today bessemers account for less 
than 5 percent of all steel produced in the United States. 
Bessemer steels are used for certain types of free- 
machining steels, certain types of wire, and some grades 
of pipe, especially pipe made by butt-welding* 



or 



15 



REFRACTORY 





TRUNNION 



GRATE 



Blowing" a bessemer at Sparrows Point. 
This is a very colorful, spectacular sight. 


















LIMESTONE 




ELECTRIC 



FURNACE 




1 



OPEN -HEARTH 
FURNACE 








STEEI 



BLAST FURNACE 




COAL 




PIG IRON 



/ COAL A 
I CHEMICALS J 










' 



BESSEMER 
CONVERTER 












PIG IRON is produced in the blast furnace. A blast of hot air is blown upward 
through the charge of iron ore, coke and limestone. The coke burns, giving off 
gases which reduce the ore to metallic iron. The limestone combines with 
impurities and forms slog. 



INGOTS are made by pouring molten steel into cast-iron molds. After the steel 
has solidified, the ingots are removed from the molds and prepared for rolling 
by reheating in soaking pits until the temperature in every part of the ingot 
is the 



OPEN-HEARTH FURNACES produce over 90 percent of all steel. Molten pig 
iron, cold scrap metal, iron ore and limestone are charged into the furnace. 
Flames sweep across the hearth, melting the charge and refining the steel. 



ELECTRIC-ARC FURNACES are e 
specifications. The charge of sel 
the molten metal is refined by b 



peciolly suitable for making steel to exocting 
ted steel scrap and limestone is melted, and 
t from the electric current. 



SEMI-FINISHING means the rolling of ingots into blooms or slabs. Sometimes 
blooms are rolled into smaller sections, called billets. The semi-finished steel — 
bloom, billet or slab — is then further rolled into the finished product. Rolling 
not only shapes the steel but also improves its mechanical properties. 



WIRE is made from coiled rod produced from billets on high-speed continuous 
rod mills. The rod is drawn through a series of dies of gradually diminishing 
size to the required gage. Some wire is then coated with zinc. 



BESSEMER CONVERTERS produce about 5 percent of all steel made in the 
United States. Air is blown through the charge of molten pig iron, burning out 
the undesirable elements which escape as gases or ore removed as slag. 



16 



BARS are hot-rolled from billets. Each pass through the rolls elongates and 
further reduces the billets in cross-section. Grooves in the surface of the rolls 
produce the proper bar shape. 




BILLET 
MILLS 





BLOOMING 
OR 

SLABBING 
MILLS 



INGOT 
POURING 




SOAKING 
PITS 










ROD AND WIRE MILLS 















BAR MILLS 





SKELP AND PIPE MILLS 





PLATE MILLS 





SHEET, STRIP & TIN PLATE MILLS 






X 



PIPE is mode from narrow strips of steel called skelp. In the continuous butt-weld 
process the skelp h automatically heated, shaped and welded. Lap-weld pipe, 
in larger diameters, is formed in individual lengths. 

PLATES are usually rolled from reheated slabs on large single-stand mills. Some 
plates are rolled to their final width on mills with vertical as well as horizontal 
rolls; others are sheared to width after rolling, 

SHEETS AND STRIP are rolled from slabs on high-speed continuous mills. After 
hot-rolling, some of this material is further reduced by cold-rolling, then annealed 
and given a final cold-rolling to improve its surface properties. 

COATINGS of tin or zinc are applied to cold-reduced sheets and strip to protect 
the steel against corrosion. Steel sheets coated with tin are known as tin plate, 
and those coated with zinc are called galvanized sheets. 

STRUCTURAL STEEL and RAILS are rolled from blooms. Standard structural shapes 
are produced on mills equipped with grooved rolls. Wide-flange sections are 
rolled on Grey mills which have ungrooved horizontal and vertical rolls. 






STRUCTURAL MILLS 






RAIL MILLS 



17 








Powerful tongs lifting an ingot from the soaking pit where 
it was thoroughly heated to the rolling temperature. 



Rolling an ingot in a reversible blooming mill. The ingot is passed 
back and forth through the rolls until it is reduced to the proper size. 




Making Finished Steel Products 



Steel leaves the open-hearth, electric-furnace and besse- 
mer departments injhe form of ingots. The sections of 
this book that follow describe how ingots are made into 
finished steel products — plates, strip, sheets, tin plate, 
bars, structural steel, wire, pipe and rails. 

Broadly speaking, ingots are processed into finished 
steel products in two steps. First, the ingot is reduced in 
cross-section by hot-rolling it into semi- finished steel 
products — blooms, billets and slabs. Second, the blooms, 
billets and slabs are processed into finished steel products. 

Preparing the Ingot for Rolling 

After the molten steel has been poured or teemed 
into ingot molds, it is allowed to cool to the point where 
it solidifies. At the proper time, the ingot mold is removed 
from the ingot by "stripping." A special crane grips the 
mold and lifts it away from the metal. Sometimes the proc- 
ess is reversed, and the metal is lifted out of the mold. 

The outside of the ingot naturally cools and solidifies 
faster than the inside. At the time the mold is removed 
the ingot is comparatively cool on the outside, but the 
interior is still extremely hot, usually in a semi-molten lnat tn< sleel to be rolled passes successivel) through each 



justed so that the rolls are always slightly closer together 
than the thickness of the steel passing through. The ingot 
gets longer and thinner as it passes between the rolls. 

The rolls are mounted in heavy housings, or roll stands. 
A stand with two rolls is referred to as two-high; a 
stand with three rolls, one above the other, is three-high. 
The ingot is carried to and through the stands on a path 
of rollers. These rollers, which are rotated by electric 
power, are mounted on the long table of the mill. 

Blooms and slabs are frequently made on two-high 
reversing mills. Since the direction of rotation of the roll- 
can be reversed, the ingot is passed hack and forth be- 
tween the rolls, which are brought closer together at each 
pass, until the steel has been reduced to the desired cross- 
section. Three-high mills are not reversible. The ingot is 
passed between the bottom ami middle rolls, then raised 
and passed between the middle and top rolls. 

Billet mills, on the other hand, are often of continuous 
design. That is. the mill consists of a series of roll stands 
I each of which is much smaller than the stands in bloom- 
ing and slabbing mills I arranged one after the other so 



condition. Before the ingot can be rolled, the outside and 
the interior must be at the same temperature. This is 
done by soaking it in heat in a soaking pit. Soaking pits 
are gas-fired furnaces where the ingot is heated to about 
2200 degrees F and kept at that temperature for from 
four to eight hours. It is then evenly heated, and soft and 
plastic enough to be shaped by the rolling mills. 

Blooms, Billets and Slabs 

Semi-finishing mills are of three principal types: 
blooming mills, billet mills and slabbing mills. As shown 
in the diagram, blooms are either square or rectangular in 
cross-section. Blooms are the form of semi-finished steel 
that is processed into large beams and girders. 

Blooms are sometimes further reduced in size to billets 
before being processed into finished products. Billets are 
used to make bars and rod. Rod is the material from 
which steel wire is made. 

Slabs are relatively flat, their width being three, four or 
more times their thickness. Slabs are used to make plates, 
strip, sheets and other flat-rolled steel products. 

Blooms and slabs are made by squeezing the hoL plas- 
tic ingot between two horizontal steel rolls rotating in 
opposite directions. The distance between the rolls is ad- 



stand and emerges from the last stand as a finished billet. 

Hot-Rolling Makes Steel Denser, Tougher 

Hot-rolling not only reduces the steel to the desired 
shape and si/e hut improves its quality. Steel consists of 
a mass of metallic crystals or grains. In the ingot these 
grains are relativeh large and are distributed in a way 
that causes poor mechanical properties. Hot-rolling 
breaks down the grains into smaller particles, making the 
steel denser, tougher and more malleable. The quality of 
the steel is improved in this way not onl\ while the ingot is 
being reduced to bloom, billet or slab, but also during 
the finishing processes that follow. 

After the blooms and slabs have been rolled their ir- 
regular ends are cut off or cropped by powerful shears. 
The cropped ends contain certain irregularities which if 
not eliminated would cause imperfections in the finished 
product. The discarded ends are used as scrap in the 
steelmaking furnaces. 

After they have been cut into shorter lengths that are 
more easily handled in the finishing mills, the b looms, 
billets and slabs are carefully inspected for defects. The 
inspector marks all surface flaws for removal by grinding, 
chipping, burning or scarfing. 



BLOOM 



BILLET 



SLAB 



19 













Highway and railroad bridges are often built largely of 
girders made up of riveted or welded steel plates and angles. 



These huge oil storage tanks, as well as water tanks, propane 
tanks, gas holders and boilers, are fabricated from steel plates. 




t 



* 



This giant hydraulic press was 
made chiefly from steel plates 
welded together. The bases, 
frames and many moving parts 
of light and heavy machinery are 
often fabricated from plates. 



» 



i 



# 



.' 



-runt ♦• 



4 •• 



< 





li' H«Wt «!!!! (Illll || 



• f •! -0(»*(i 



• f 



• • 



• • 





Slab entering sheared-plate mill at the Sparrows Point Plant. 
This thick slab will be rolled down to less than Vi inch in thickness. 




After rolling, the plate passes through special leveling 
rolls while still hot, making it perfectly straight and flat. 




Plates are one of the basic forms of finished steel. 
They range in thickness from about 3/16 inches to over 
12 inches. Girders and other components of bridges and 
buildings are often made from plates, as are the hulls and 
decks of many seagoing vessels. The bases that support 
large machines, as well as many machinery parts, are 
frequently made from plates. Boilers, oil and water stor- 
age tanks, gas holders and propane tanks; large-diameter 
pipe for water, oil and natural gas, and innumerable 
varieties of industrial processing equipment, are other 
typical examples of steel-plate construction. 

Two Methods of Rolling Plates 

Plates are rolled from slabs on either of two types of 
plate mills: sheared or universal. Plates produced on 



sheared-plate mills must be cut on all sides to the desired 
dimensions after rolling. Universal-plate mills, having a 
set of vertical edging rolls in addition to their horizontal 
rolls, roll plates to accurate width, with straight and 
parallel rolled edges, so that shearing is not necessary. 

A substantial tonnage of plates, usually in the lighter 
gages, is produced on the continuous strip mill, which is 
described in the following section. 

Before it is rolled the slab is placed in a furnace where 
it is slowly heated to the rolling temperature. At the 
proper time the hot slab is removed from the furnace 
and taken to the universal or sheared-plate mill where it is 
rolled and is made perfectly flat by passing it through a 
set of leveling rolls. Finally, plates made on the sheared- 
plate mill are sheared to size. 








iibiiiii 111 iiiiiinn 



iiHiinii in iibiiiii 



f ' 



w 



21 



Many thousands of tons of steel plates were 
used in building the 30,000-ton S.S. Inde- 
pendence. The ship's huge hull, the funnels, 
masts, decks and much below-decks equip- 
ment were fabricated from steel plates. The 
Independence and her sister ship, the Con- 
stitution, were designed and constructed by 
Bethlehem's Shipbuilding Division. 




t ? 



r-* 



r- * 



- •■' 



- 1 



^m 















22 



Of all the forms of finished steel products, nohe is more 
widely used than sheets and strip. Automobile and truck 
manufacturers use huge quantities of steel sheets and strip 
for auto bodies, hoods, fenders and door panels. Many 
types of metal furniture — desks, chairs, and filing cabi- 
nets — ar e made from steel sheets. So are household 
appliances — refrigerators, ranges, washing machines 
and cabinets — as well as metal containers, like barrels 
and drums, and an endless variety of parts for many 
kinds of mechanical equipment. 

The Continuous Mill in Action 

The first step in making sheets and strip is hot-rolling 
on the continuous hot-strip mill, one of the production 

marvels of our time. 

First, the slab is heated to the proper rolling tempera- 
ture. The glowing slab is pushed from the furnace onto 
a line of revolving rollers which carry it to the scale- 
breaker, a set of rolls which breaks up the oxide scale 
formed on the surface of the slab during heating. A pow- 
erful water spray then washes away the loose scale. 

The slab moves through the roughing stands which 
squeeze it down to about one-fifth its original thickness, 
and stretch it to about five times its original length. 

From the roughing stands the slab passes through a 
second scale-breaker and also a shear which cuts off the 
uneven ends formed during roughing. 

Next, the slab enters the finishing stands — a series of 
six huge roll stands. When it enters these stands it is from 




Strip emerging from the hot-strip mill at Sparrows Point, In the 
background, a roughed slab approaches the finishing stands. 



60 to 70 feet long. It leaves the stands as 600 to 700 feet 
of hot-rolled strip. Since each stand reduces the strip by 
about one-third in thickness, each succeeding set of rolls 
must be adjusted to r\m half again as fast as the preceding 
set. The steel lengthens so rapidly that before the trailing 
end of the strip has entered the first stand, the leading end 
has passed through all six stands, raced down the long 
runout table at a speed of from 20 to 25 miles per hour, 
and reached the automatic coiling machine, about 1200 
feet from the heating furnaces. 



accurate dimensions and gives it a smooth, bright surface. 
Cold-reduced sheets, generally after further processing, 
can be drawn or pressed into a wide variety of shapes 
such as automobile bodies. 



Steel is Cleaned Before Cold-Rolling 

The cold-reduction process requires that the metal be 
quite clean and free of the scale that forms during hot- 
rolling. This scale is removed by pickling, or passing the 



A trap door directs the fast-moving strip down into hot-rolled strip through a hot solution of dilute sulphuric 

the coder, which is located beneath the runout table. In acid. After pickling, the steel is washed, first in cold water, 

less than 20 seconds the ribbon-like strip is wound tightly then in hot water and in steam, to remove any remaining 

into a heavy coil. The coil is ejected, then placed on a traces of scale and acid. Then the strip passes between 



mechanical conveyor which carries it to storage. 



two rubber rolls which squeeze off the water. It is dried 



Sometimes the strip is cut into sheets instead of being D > jets of warm air. and is lightly coated with oil to 

coiled. This is done by a flying shear located immediately prevent rusting. 

back of the last finishing stand. The shear, which is Cold reduction is usually done on three-, four- or five- 
equipped with rotating knives, automatically cuts the stand, four-high mills. B\ sheer pressure the huge rolls 
strip into sheets of the desired length. These sheets then reduce the cold steel to perhaps one-tenth its original 
travel down the long runout table to be stacked l>\ an thickness. The process is so fast that up to 3500 feet or 



automatic piler. 



Further Rolling on Cold-Reduction Mill 

Much of the strip rolled on the continuous hot-strip 
mill is further processed on the cold-reduction null, which 
can produce thinner steel than it is feasible to roll on 
the hot mills. Cold rolling also finishes the strip to more 



more of cold-rolled strip can be produced per minute. 
After leaving the cold-reduction mill, the strip, now 

with a smooth, lustrou- surface, is coiled again and ma\ 
later be sheared to sheet .sizes. 

A great deal of cold-rolled sheet and strip, particularly 
of the lighter gages, is coated with other metals — zinc 
or tin. Zinc-plating or galvanizing and tin-plating an 
described on the following pages. 



23 




Hot-rolled strip speeds at 25 miles per hour down the runout table 
of the continuous hot-strip mill, through a trapdoor to the coiler. 




' 






The enameled panels of many household appliances, stoves, refriger 
ators and cabinets are made from hot-rolled, cold-reduced sheets 



Cold-rolled strip is softened by annealing, then passed through this single-stand 
skin-pass mill. Skin-passing stiffens the steel and gives it a highly polished surface. 




Annealing and Skin-Pass Rolling 

Cold working hard* steel, making it < \< sivel) ^tiff. The 
nee* >oftn< and ductility are i tored 1>\ anneaUn 

The sheets or strip are pk I in gas-fired annealing furnace 
which at held aL the proper temperatu for a specified 
Length of timi The steel is then - >ved and pa 1 through 
kin-puss null, us u all) co ting of a single four-high I. 

kin-p oiling redu - thi thickness slightly jives tin* sfc 
|)j lii sheen, and resto - jusi the correel lount of stiff- 
n Finally, the si its or coils are jcted for proper 

h. tern] and flatness. 

Galvanized Sheets Have Many Uses 

I sheet steel are galvanized, coated with 

/mi !■! |. ,a >l rust or corrosion, i in i/ed steel 

I to i <ln« h as i i buckets, ■ i ans, 

»r i ool md sidiiij and foi duel w ork 
ii I I ventilatii »nd 

Hrav >f tnized si made f« \ hot- 

.'lit i im sh< Is thai have 

I i above. I w o n Is of ling 

J sh strip with zin< in u y. In the hot-d ip 

I the /in< roatinjj i|»pl . pass rig individual 

^t. -h« h I i /in- i other method, 

n ei ! 1\ I t. efficienl »j>era- 

tion in n> I strip is I >ugh the at) 

t o sh 



24 




Steel is often golvonized for 
protection against corrosion. 





H Elc olytically coated *t rip leaving the 
plating line at Sparrow* Point tin mill. 



Man oyt are made of tin-mill block plate 




So-called "tin cans," bottle caps and containers 
for candy, adhesive bandages, shoe polish 
and floor wax are made from tin plate. 




You can realize the importance of tin plate when you 
consider that about half of all the food we eat is packaged 
in cans made of tin plate. Many people are surprised to 
learn that so-called "tin cans" actually consist of almost 
99 percent steel and only 1 or 1% percent tin. The pur- 
pose of the light coating of tin on the outside and inside 
is to protect the steel from corrosion, and to impart an 
attractive, durable surface. 

Preparing Steel for Tin-Plating 

The first step in making tin plate is the preparation of 
extremely thin sheets and strip, called tin-mill black plate. 
This is done by cold-rolling as described in the preceding 
section, although slightly different equipment must be 
used in order to reduce the steel to the extreme thinness 
required for tin-plating. 

An interesting sidelight is the fact that, due to its thin 
gage, tin-mill black plate is used in making Venetian 
blinds, toys and many other light articles. 

Before the tin coating can be put on it, black plate must 
be perfect in two respects. First, it must be almost surgi- 
cally clean. Second, it must be slightly etched so that the 
tin will readily adhere to its surface. These requirements 
are met by pickling the coils or sheets in a very dilute 
solution of sulphuric acid which removes any surface 
rust or specks of dirt, and lightly etches the metal. 

Two Methods of Tin-Plating 

Hot-dip tin-plating is the older method of producing 
tin plate. In this process, sheets of tin-mill black plate 



are fed automatically into rolls which guide the sheets 
through a pot of molten tin and up through a pot of palm 
oil containing rolls which control the thickness of the 
tin coating and distribute the tin evenly over the sheets. 
The coated sheets pass through a stream of bran which 
takes off the excess oil. and are finally polished by cloth- 
covered rolls revolving in finely-powdered bran. 

The sheets of tin plate are then taken to a well-lighted 
room where they are carefully inspected before shipment. 
The slightest imperfection results in a rejected sheet. 

Electrolytic tin-plating, like many other technical ad- 
vances, was developed under the pressure of wartime ne- 
cessity. During World War II there was a shortage of tin. 
As a much lighter coating can be applied electrolytically 
than by the hot-dip method, the electrolytic process was 
developed to conserve the available tin supply. However, 
certain heavy coatings can also be applied economically 
by this process. 

Electrolytic tinning, which is faster and more efficient 
than the hot-dip method, is a continuous process. Long 
coils of prepared tin-mill black plate are fed through an 
electrolytic bath, in which a uniform coating of tin is 
deposited on the steel by the action of an electric current. 
The gleaming steel strip speeds through the bath at 450 
to 1200 feet per minute, then passes through a furnace. 
The hear, melts the tin which flows, forming a lustrous 
coat. From the electrolytic line, the strip is carried to 
rotary shears which, cut it into sheets. These sheets must 
pass both an electric-eye and an expert visual inspection. 



25 




The dominant building material of the Twentieth Cen- 
tury is the structural steel shape. Structural shapes and, 
in particular, the wide-flange shapes which were first 
produced in America by Bethlehem in 1907, made pos- 
sible the skyscrapers of modern America. Many of the 
towering buildings and bridges that are the construction 
marvels of our time derive their strength from sturdy 
tructural steel shapes. 

Rolling Structural Steel 

Structural steel is produced in a number of standard 
sections: I-beams, channels, angles, tees and zees. They 
are made by passing steel blooms between grooved rolls, 
the action of the rolls squeezing the hot plastic steel into 
the grooves. In this way the bloom is altered a little 
more fr i its original shape on each pass until, passing 
through the final grooved roll-, it emerges with the de- 
sired shape and size. 

It is obviously no simple matter to change the cross- 
sectional shape and area of a large, square bloom into 
an I-beam. The process may require as mam as twenty- 
six roll passes. The first few passes are chiefly designed 
to reduce the bulk of the bloom. Succeeding passes 



gradually form the blank into the final shape. 

While standard structural shapes are formed on mills 
with grooved horizontal rolls, wide-flange shapes are 
rolled on special reversible mills known at Bethlehem as 
Grey mills. Instead of grooved rolls, which it is not feasi- 
ble to use for rolling shapes with wide flanges, Grey mills 
have smooth, relatively narrow horizontal and vertical 
rolls which may be spread or closed between passes. The 
horizontal rolls work on the center portion or web of the 
beam between the flanges and on the inside faces of the 
flanges. The vertical rolls work on the outside faces of 

the flanges only. 

After they have been rolled to the desired cross-section, 
tructural shapes are straightened and cut to length. 

Fabricating and Erecting Steel Structures 

Bethlehem not only produces structural steel shapes, 
but also fabricates and erects steel structures of all types. 
The steel frameworks of many of America's landmarks — 
the Golden Gate, Chesapeake Bay and George Washing- 
ton bridges, New York's Waldorf-Astoria Hotel and Chi- 
cago's Merchandise Mart — were fabricated and erected 
b\ Bethlehem's Fabricated Steel Construction Division. 



26 



Roiling a wide-flange structural beam on a 
Grey mill at the Bethlehem Plant. The smooth, 
narrow horizontal and vertical rolls are visible. 



The 4-mile-long Chesapeake Bay Bridge near Baltimore, opened for traffic in 1952, 
is the third longest bridge in the world, and the first to span Chesapeake Bay. The super- 
structure of 30,000 tons of structural steel was fabricated and erected by Bethlehem. 






Bethlehem fabricated and erected John Hancock Mutual life Insur 
ance Company's handsome home office in Boston, Mass. It is twenty 
nine stories high and contains 14,700 tons of structural steel 




This is a new power plant on Lake Erie near Detroit, Mich. Its main 
boiler room is about as high as a 1 6-story building. Bethlehem sup- 
plied the structural shapes for the framework of this huge structure. 



The 43-story Waldorf-Astoria in New York City 
has a framework of 25,000 tons of Bethlehem 
structural steel. Bethlehem also fabricated and 
erected the steel for this monumental building. 



A striking building in a glittering setting, this de- 
partment store in Beverly Hills, Calif, was fabri- 
cated and erected by Bethlehem Pacific. Structural 
steel often makes possible such modern design. 







The important role of steel bars is brought home by 
the fact that over 600 pounds of bar steel go into the 
average passenger automobile. Crankshafts, connecting 
rods, spark plugs, axles, tire rims, door hinges and many 
other vital parts are formed from various grades of car- 
bon or alloy-steel bars, or special shapes rolled as bars. 
The average farm tractor contains 900 pounds of steel 
bars; the average diesel locomotive, over 17.000 pounds. 
Many everyday hand tools — knives, axes, hammers, 
pliers and wrenches — and various parts of every type of 
power-driven machinery are made from steel bars. In 
addition, many thousands of tons of reinforcing bars are 
used every j ear in the construction of concrete buildings, 

highways and bridges. 

Steel bars come in many different shapes, the most 
common ones being round, square, hexagonal, octagonal, 
half-round, oval and flat. 

Bars Are Rolled on Merchant Mills 

There are many types of bar mills, all of which are 
commonly called merchant mills. They vary from the 
highly mechanized continuous bar mill to the hand mill, 
where workmen use long-handled tongs to guide the steel 



through the rolls. 



Continuous mills, having great productive capacity, are 
used to produce high tonnage products — the simple 
standard bar sections, which include reinforcing bars. 



28 



Spark plugs, crankshafts, camshafts, valve lifters and connecting 
rods are among the many automobile parts made from steel bars. 



Rolling bars from billets on a bar mill at the Los Angeles 
Plant. The entire operation takes less than two minutes. 





I 



Other tyr*- of milk a* not as fast but an reflet 

Hi ■ *' '< trallv used to prodc th- m , , x 

From Billet to Bar in 2 Minutes 

ln ■ modern big] I eontin ■> bur /.ill. tl ,t 

billet betw I..., ine&ettqiu . ross 
from 16 to K) feel leu i V , r«rne. »tfc 

roughii train Growii tdiK -I .-, ,,,,1 I 

'' '«' ■« I'M' M' ! f ''l"..jrt 10 mil , I r , 

11 'I "' bei to i). ,j„ ,.<k ia tl tap 

fii bed bei If,. ,„i tI , ,.■ f, 

""• I dfa I o Mil) takes lew tl i i i* 

I bi |.i... -• in- .it, , , 00 |i, . , ra j | ! 

"din ' ' tbr i ,- „f f,,,, rolled ....l 

"•' !''■ ning, cutting to .-, ,i„-,l iV,,.mI .,t-i 

i.__ -_.i ii i 



lone. ^ I ii 1'in i if.-- total Ln mi ...f 

row iM.ii.iiul f.,i colli «lruwiii| forgii \mr of, mm- 

■ I'iihipk <•■ Mil rations. 

Cold Drawn B.irs 

\ COMHIilri.ililr h.liliagl hot rollril |,.ir^ ,| i C« 

.Iniwn through in M fi|M*ralion i illi umils 

hi. .ii .win ll, , «s» make 

I" 1 ' • *'" 'I' b III .in I i. . I: (,,■„ if tl. | 

1,11 '. 'I.I.I >• It IS III.,, .,H If, „ J, 








M 



C#r ttun prop* *« of hot rolled bar\, iueh en ducttft 
QT9 improved by annealing in rurnac«t %uc h .m 









b.l.f 








■w^ , feoff 




■ 



r 










Steel wire is one of the most versatile and most widely 
used of all steel products. It has thousands of applications, 
including innumerable products that we use every day. 
Fasteners of all sorts, from spikes to staples, nails, screws, 
paper clips, pins, tacks and many types and sizes of bolts 
are made from steel wire. Springs for machinery and for 
furniture, farm fences, mesh for screen doors, bicycle 
spokes, coat hangers, chains, piano wires and kitchen 
utensils — all are made from steel wire. 

All steel wire is cold-drawn from hot-rolled rod. Rod, 
in turn, is rolled from billets, generally between 1% and 
3 inches square in cross-section, and about 30 feet long. 
Depending on the design of the mill being used, from two 
to four billets producing an equal number of strands of 
rod may be rolled simultaneously, side by side. 

Rolling Rod from Billets 

These billets are uniformly heated to the proper rolling 
temperature in a special furnace, then fed into a continu- 
ous rod mill. Continuous rod mills of the most modern 
type generally consist of two main sections — a set of 
roughing stands and a set of finishing stands. The total 
number of stands is usually over sixteen. 

As they enter the "bite" of the first roughing stand, 
the billets are traveling at about 10 miles an hour. They 
pass from stand to stand, growing thinner and longer — 
and therefore moving faster — at each pass, until the fin- 
ished rod speeds from the last finishing stand at between 
40 and 50 miles an hour. The rod is then quickly coiled. 

During the hot-rolling process a 30-foot-long billet may 
be lengthened to nearly a mile. The whole operation takes 



30 



Thousands of miles of farm fence and barbed 
wire are made from steel wire every year. 



Housewives use many utensils made of steel wire — 
tongs, cheese sheers, wire brushes and bottle openers 





«-»' 







ju-i a little over one minute I rete reinforcing har- 
a- well as rod*, are turned out bj tome rod milk 

VI in m made by pulling rod through tapered holes or 
'/ . slightly smaller in diameter than the rod itself. In 
this way the diameter of the rod u eased while th 

length i- increased The usual arrangement m to dl the 
rod through a serie- of su' ceafti K -muller die- until th 

finished wire ia of the de-n.-d , 



Drawing Wire from Rod 

In |»i-[ ( .Hing .1 for wire di twin the hi i to 

rernov.- the oxide fcale which forms after hotrollm 

I In, t~ don.- I»\ pickling the d rod in hot lot d- 

plmiM arid When the »caJe hae been i .»ovr-d tin 

is bathed in water win. h w hes away the 8' id Next 



r,M ' »-■ <iip|i<-<l in t lime lolution thru i* halted in .in . 

f" fix ll.r time I ihfiK I hii roatii 1,1 

f<" the \u\nu .ml it,., I raM-, th .1 through thr 

I h« jm tarrd * oil i. pi.,, nl »n i rr*eJ B1 the i | 

J, *K niiicl ir idr md oi the rod poii -I »ta 

through the i a\»-n& dii I h< ■ ■!■ h I 
rh"d libetii- miK I. hardei than th I i 

Mter poaeing through the di the rod ii ,*•* eruun 

ii power-driven drum or block \ this block I 

pulN iIm km) through the die ln< ontinooue * iwn 

the rod ii drawn through » lei rf di i I i round I 

< ontinuoui in/ii drawing ii limil u ti on - roll 

«" In that the ateel iduallv rrdu ncroeeaecti 

ami it. U ..-Ml. propOfti m< rea^ I hrr - 

iIm* wire- in * along friuii die to di 






u 



ding 



drum must rotate faster t accommodate the length 
wire. On leav ing the last die the smaller sizes of win 
travel as t e niles an hour. 



Heat-Treating Restores Ductility 

*"* tr in of Id-draw g hardens the 

1 to **** I it ca t I iwn an\ forth 

1 - VW L ng l- |r 



i A tfr 



- an«l 






stored I at dii the i during i m atr 

t drawing | | after hnal di 
\notr 






the production 

win Rim i Q g | ** w \ 

need to jm. • n { 

•vii rid also i A | 



- * I i 1 j 



if 






l >tJ 
>oling tl 



. i 






V 



I rapidl 



v l 



peral Patenting »Ui 

a lonjj : then 

final -n Ira, I 



Two Methods of Zinc Coating Wire 

V it ll i r,i 4 | I* il 

wild ii rusi 



tv\ 



i r i r m 

If hr- h liD 






the hm <i 



h 



U 



*/> | %* illltl tlir 






m ,1 







i 



frrtnda 






I 



1 tl 

I'd I 

it paaee* r 









/in« i* 



v% II n r|# | 

- * 



all 









OS I' 

" fhii i 



* ei a m m,l rnJ> I 

thai h«»t ilii. 



I«*d ( tuig 



31 



Th«% vifw . t q conhnuom rod mill *ho* 
the multaneCHM rolling of four \trond 



B- ^g *n» r# 

in at •' pa% jh tuc d«#. oi%« 






Laying a natural gas 



line of electrically welded steel pipe. This pipe is also used to carry gasoline, crude oil, water and sewage. 



.H 





Tubular products— pipe and tubes — are either welded 

or Welded pipe is made by forming flat steel 

into cylindrical shape and welding the edges together in a 

long welded seam. Seamless tubing is made by piercing 

solid bars and billets, and therefore has no weld seam. 

Steel pipe is made in diameters ranging from fractions 

f an inch up to 12 feet or more. The smaller sizes are 

xtensivelv used in plumbing and heating systems, and 

in countless industrial applications. The large sizes are 

used mostly in cross-country pipe lines for oil and gas, 

and in water and sewage systems. 

Steel tubing, due to its lightness and strength, in addi- 
tion to carrying gases and liquids is widely used for 
structural purposes. Bicycle frames, flag poles, airplane 
bodies, furniture and playground equipment, are among 
the many structural applications of steel tubing. 

Continuous Butt-Welding 

Welded pipes and tubes are made by three methods: 
continuous butt-welding, lap-welding and electric weld- 
ing. Seamless pipes and tubes are made by the piercing 
prort described later. 

W ded pipe from ] 2 inch to about 4 inches in diameter 
is usually made on the continuous pipe mill. Steel in the 
form of long strips, called skelp. d into a furnace 

where it is heated to the welding temperature. The skelp 
th< moves through a series of roll-passes, consisting of 
multiple pairs of horizontal and vertical rolls. The rolls 



form the moving skelp into a cylinder, welding together 

the heated edges. 

As the pipe leaves the rolls, a saw cuts it into lengths. 
After it has cooled, the pipe is straightened and threaded. 
The strength of the weld is tested hydrostatically, by 
sealing the ends of the pipe and pumping in water under 
high pressure. Pipe is often galvanized, by coating it with 
zinc, to protect it from corrosion, 

Lap-Welding 

Pipe between 4 and 16 inches in diameter is made by 
lap-welding. Lengths of skelp are heated, the edges are 
beveled, and the skelp bent into a cylinder with over- 
lapping edges. This bent skelp is then reheated to welding 
temperature and drawn over a welding ball held between 
two rolls. As the hot skelp passes over the ball, the rolls 
press the lapped edges against it, automatically welding 
the edges together. 

After welding, the pipe passes through a set of sizing 
rolls. Then it is straightened, allowed to cool, threaded 
md hydrostatically tested. 

Electric Welding 

Electric-weld pipe is made in sizes up to 150 inches in 

diameter or more, the upper limit being governed by 
-hipping clearances rather than manufacturing limita- 
tions. The large-diameter steel pipe used to carry oil, gas 
and water long distances is made by electric welding. 
Electric-weld pipe is made from plates, usually 20. 30 



32 




Small-diameter pipe is formed by continuous butt-welding. 
Skelp is welded into pipe as it passes through sets of rolls. 




Curved steel plates are fed into this electric welding machine which 
welds the edges together, forming large-diameter steel pipe. 



or 40 feet long and often over 1 inch thick. First, all four 
edges of the plate are planed in order to assure a tighl 
joint when welded. The long edges are crimped, then 
powerful rolls bend the plate into cylindrical shape. Th 
lonned plate, held in shape by temporarj or ' 4 tack' 1 

welds, is then welded on a large elerli ie-fusion welding 
machine. A hydrostatic test insures the strength ol th 
weld and freedom from leaks. 

Making Seamless Tubing 

Seamless pipe and tuhing is made from tube rounds, 
a form of semi-finished steel, by a number of methods. 



I" one of iht pm. 9 a tuhe round, preheated to a 
uniform working temperature, passes between a pair of 
rotating crossed rolls. The rotating action of the rolli 
forces one end «>l the round againsl a piercing plu^ or 
landrel. The combined rolling ction and the pressure 
ol the rolls tends t<> open the round al Us center. The 
mandrel controls and completes this piercing action. 
The resull is a rough tube which is then finished b) pass 
ing it through a 9et ol rolls over a ball in a process imilar 
to the finish-rolling of lap-welded pipe. Various ingeniou 
procedures make it possible iccuratel) to control the wall 
thick? 5s and the outside diameter of the tubing. 



33 




1 




4 





2 




5 




3 




6 




A few of the steps in rolling rails. These simpli- 
fied diagrams illustrate how a bloom is gradu- 
ally shaped into a rail by the action of the rolls. 




Steel rails for America's railroads were first made m this 
country in 1867 at what is now Bethlehem's Johnstown, Pa 
Plant Today, rails remain one of the most important of all 
finished steel products. The safety of millions of travelers 
depends on the quality of these rails. Rails have to stand up 
under fast, heavy trains and endure the strains caused by 

severe weather conditions. 

Large quantities of heavy rails are produced for railroads. 
Lighter rails are made for haulage systems in mines and 
industrial plants. Besides producing rails, Bethlehem fabri- 
cates track layouts, including curves, crossings and switches. 

Rails Are Rolled from Blooms 

A roughing mill reduces and forms the reheated bloom into 
the approximate size and shape of a rail. Then, passing 
through a number of finishing stands, the steel is formed into 
T-shaped rails, sometimes as long as 120 feet, which are hot- 
sawed to standard 33- or 39-foot lengths. 

After cooling to some extent on the mill hot beds, the 
heavier rails used in main-line service are placed in long 
covered metal boxes for contr oiled-cooling, a process devel- 
oped by Bethlehem. This process eliminates dangerous trans- 
verse fissures or "shatter cracks" which might otherwise form 
during cooling. Another Bethlehem development is end-hard- 
ening, a method of heat-treating which hardens the ends of 
rails so they can withstand wheel battering at rail joints. 

In order to provide rails that can better stand up under the 
severest conditions of modern railroading, Bethlehem has 
introduced heat-treated rails and trackwork. Heat-treatment, 
which includes oil-quenching and tempering, improves the 
physical properties of rails for use at points of unusual stress. 



34 



Bethlehem produces all types of steel rails in- 
cluding both light rails for mines and indus- 
trial plants, and heavy rails for the railroods. 







Pig Iron 



Plates 



Wire Rod 



Roils 



Structural Shapes 



Pipe 



Wire 



Bars 



Special Rolled Sections 



Concrete Reinforcing Bars 



Carbon, Alloy and Special Steels 



Tool Steels 



Coal Chemicals 



Ferro-Manganese 
Steel Piling 



Sheets and Strip 



Tin Mill Products 




Bridges, Buildings and Other Structures of All Kinds 

Steel Freight and Mine Cars 
Wrought Steel Wheels and Axles for Railway Equipment 



Rolls — Steel and Cast Iron 



Flanged and Dished Heads 



Nails, Staples, Barbed Wire and Bale Ties 
Open-Web Joists and other Construction Specialties 



Forgings 



Trackwork and Trackwork Accessories 



Tools 



Bolts, Nuts, Rivets, Spikes and other Fasteners 



Gear Blanks 



Wire Rope and Strand 



Hydraulic and Special Machinery 



Guard Rails, Posts and Highway Specialties 



Farm Fence and Posts 



Castings — Steel, Iron, Brass and Bronze 



Oil Well and Refinery Equipment Tanks and other Weldments 



35 



INSIDE COVER 



Wide-flange beams awaiting shipment at the Bethlehem Fabricating Works Holes have 
r.en punched in the beams so that they can be quickly erected at the bu.ld.ng s.te. 




Lobby of Bethlehem Steel Company's general office building at Bethlehem, Pennsylvania. Reception desk 
is shown at the head of the stairway with elevators in background and waiting alcoves along either side. 



BETHLEHEM 

Sfeef and I or Manufacturing Plants 



Bethlehem, Pa. 
Corsicana, Tex. 
Johnstown, Pa. 



Seattle, Wash. 

So. San Francisco, Calif. 

Sparrows Point, Md. 



Lackawanna, N. Y. Steelton, Pa. 



Lebanon, Pa. 



Tulsa, Okla. 



Los Angeles, Calif. Williamsport, Pa. 

Fabricating Works 



Alameda, Calif. 
Bethlehem, Pa. 
Buffalo, N. Y. 




Chicago, 
Leetsdale, Pa. 



Los Angeles, Calif. 

Pottstown, Pa. 

Rankin, Pa. 

So. San Francisco, Calif 

Steelton, Pa. 




Seattle, Wash. 

Shipbuilding and Ship Repair Yards 

Baltimore, Md. 
Beaumont, Tex. 
Boston, Mass. 
Brooklyn, N. Y. 
Hoboken, N. J. 



Quincy, Mass. 
San Francisco, Calif. 
San Pedro, Calif. 
Sparrows Point, Md. 
Staten Island, N. Y. 



BETHLEHEM STEEL COMPANY 

General Offices: Bethlehem, Pa. 

BETHLEHEM PACIFIC COAST STEEL 

CORPORATION 

General Offices: San Francisco 



Booklet 363 



54 7 Printed in U.S. A 



BACK COVER 
Lifting o glowing ingot from a soaking pit at the 
Johnstown Plant. The ingot is now ready for rolling. 



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